Comparison of corneal horizontal diameter and axial length of myopic people of different ages

Abstract

Objective To explore the changes of corneal diameter and ocular axis in different age groups of myopia. Methods 270 cases (497 eyes) of myopia were selected from August 2015 to August 2017 in Foshan ALR ophthalmology hospital. According to the age is divided into three groups, respectively is 7~17 years old group, 18~28 years group and 29~39 years group, 90 cases in each group; the cycloplegic refraction spherical equivalent measurement of the degree of myopia was detected in three patients, according to the degree of myopia re grouping, grouping criteria for low myopia than -3.00 D, were moderate; -3.25~-6.00 D, >-6.00 D for high myopia myopia; The corneal diameter of the patients was measured by Pentacam, and the axial length of the patients was measured by IOL master. The length and diameter of axis(±s)in the form of description, compared with analysis of variance between different age groups, the difference was statistically significant when compared further 22. Results Low myopia, three groups of patients with horizontal corneal diameter were (12.01±0.41)mm, (11.70±0.36)mm and (11.62±0.42)mm, among them, there were statistically significant differences between 7~17 years group and 18~28 years group (t=2.64, P 0.05). The axial length of the three groups were (24.63±0.61)mm, (24.53±0.80)mm and (24.53±0.93)mm, respectively. There was no significant difference between the two groups (t=0.77, 0.65, -0.05; P>0.05). Moderate myopia, three groups of patients with horizontal corneal diameter were (11.89±0.39)mm, (11.71±0.33)mm and (11.63±0.37)mm, among them, there were statistically significant differences between 7~17 years group and 18~28 years group (t=2.64, P 0.05). The axial length of the three groups were (25.12±0.75)mm, (25.17±0.85)mm and (25.23±0.73)mm, respectively. There was no significant difference between the two groups (t=-0.33, -0.78, -0.39; P>0.05). Three groups of patients with high myopia, the corneal horizontal diameter were (11.82±0.34)mm, (11.72±0.36)mm and (11.39±0.40)mm, among them, there were statistically significant differences between 7~17 years group and 29~39 years group (t=5.95, P 0.05). The axial length of the three groups of patients were (25.99±0.74)mm, (26.42±0.84)mm and (26.01±0.85)mm, among them, there were statistically significant differences between 7~17 years group and 18~28 years group (t=-2.84, P 0.05). Conclusions In patients with eye height, moderate and low myopia, corneal horizontal diameter was negatively correlated with the growth of the age, which is the value of corneal horizontal diameter will decrease with the increase of age; while axial lengt and refractive error was positively related to axial lengt, which will increase with the increase of refractive errors, but in each group, axial lengt the change has nothing to do with age. Key words: Age; Myopia; Corneal horizontal diameter; Axis lengt